// import org.json.simple.JSONObject;


class JsonEncodeDemo 
{
    public static void main(String[] args)
    {
        JSONObject obj = new JSONObject();

        obj.put("name", "foo");
        obj.put("num", new Integer(100));
        obj.put("balance", new Double(1000.21));
        obj.put("is_vip", new Boolean(true));

        System.out.print(obj);
    }
}